1. Field of the Invention
The present invention relates generally to media storage libraries and more specifically to a mechanism for switching between alternate guide rail paths for robots.
2. Background of the Invention
Typical library designs using more than one robotic accessor have contention problems. For example, when one accessor is moving toward a tape reader unit another accessor will want to move away from the unit, and their paths must meet somewhere. This effectively causes performance degradation and makes the control of the robots extremely complex.
Library performance is determined by robot availability during periods of high activity. Especially with single-robot systems, the mount time for a job is dependent on the dismount time. Multiple robot systems provide more accessories for higher availability, but the mechanical and software components of a typical library system are not designed to unlink the mount time from the dismount time.
For libraries using horizontal storage arrays, efficient mounting and dismounting of media cartridges, as well as avoidance of robot contention requires the ability of robots to smoothly move between horizontal levels and loop around the library.
Therefore, it would be desirable to have a system that allowed robots in a horizontal storage library to switch between horizontal and vertical guide tracks, without complex software or hardware requirements.
The present invention provides a guide rail switch for a robotic track system, the robotic track system comprising at least one horizontal guide rail, at least one vertical guide rail, and at least one robot that can move along the guide rails. The switch comprises a frame coupled to the horizontal guide rail and the vertical guide rail, and a moving joint coupled to the frame, wherein the moving joint can move between a first and second position. A first rail section is coupled to the moving joint, wherein the first track section connects to the horizontal guide rail when the moving joint is in the first position. A second rail section coupled to the moving joint, wherein the second track section connects to the vertical guide rail when the moving joint is in the second position. This switch allows the robot to move between the vertical and horizontal rail depending on which position the switch is in.